One-week ranitidine bismuth citrate versus colloidal bismuth subcitrate-based anti-Helicobacter triple therapy: A prospective randomized controlled trial

OBJECTIVE: The efficacy of 1 wk bismuth triple therapy is adversely influen ced by the presence of metronidazole resistance. In vitro studies suggest t hat ranitidine bismuth citrate (RBC) plus metronidazole exhibit synergistic activity against metronidazole resistant strains of Helicobacter pylori (H . pylori). Whether this confers a superior clinical efficacy remains unprov en. This study compared the efficacy of RBC-based triple therapy with bismu th triple therapy in eradication of H. pylori. METHODS: Patients with H. pylori-related ulcer disease or gastritis were ra ndomized to receive either 400/mg of RBC twice daily plus 400/mg of metroni dazole and 500/mg of tetracycline four times daily for 1 wk (RMT) or 120/mg of colloidal bismuth subcitrate, 400/mg of metronidazole, and 500/mg of te tracycline, all given four times daily for 1 wk (BMT). Metronidazole suscep tibility was determined by the E-test and pretreatment resistance was defin ed as minimum inhibitory concentration greater than or equal to 32/mg/L. RESULTS: Of 100 consecutive patients randomized, two patients were lost to follow-up in each group. Forty-three of 85 (51%) H. pylori isolates were me tronidazole resistant. Perprotocol cure rate for RMT and BMT was 49 of 41 ( 98%) and 37 of 44 (84%), respectively (p = 0.058). Intent-to-treat cure rat e for RMT and BMT was 46 of 50 and 41 of 50, respectively (92% vs 82%,p = 0 .23). A significantly higher eradication of metronidazole resistant H. pylo ri was observed in the RMT group (25 of 25, 100%) than in the BMT group (12 of 16, 75%), (p = 0.018). Side effects observed in the two treatment group s were comparable. CONCLUSIONS: One week of RBC triple therapy with metronidazole and tetracyc line is an effective anti-Helicobacter therapy. This regimen is more approp riate in areas of high prevalence of metronidazole resistance. (Am J Gastro enterol 1999;94:721-724. (C) 1999 by Am. Cell. of Gastroenterology).